B型DNA双螺旋结构要点？ 右手螺旋，反向平行；螺旋直径2nm；脱氧核糖和磷酸基主链位于螺旋外部，碱基位于螺旋内部；双螺旋的螺距为3.4nm，其中包含10个核苷酸对
u字母和什么相拼时不要头上两点
英语hat翻译成语文是什么 hatnouna shaped covering for the head worn for warmth，as a fashion item，or as part of a uniform帽子used to refer to a particular role or occupation of someone who has than one.（有多种职务或职业者的）职务，头衔wearing her scientific hat she is director of a pharmacology research group.作为科学家，她同时又是一个药理学研究组的主任.习惯用语be all hat and no cattle(US informal)tend to talk boastfully without acting on one's words(美，非正式)空谈，夸夸其谈black hat(或 white hat)used in reference to the bad(or good)party in a situation(from the colour of hat traditionally worn by the bad(or good)character in Western films)〔用于指西部片场景中可通过帽子颜色判断出来的坏人或好人〕黑帽（或白帽）we are the good guys—the black hats lost.我们是那些好人—黑帽子坏人输了.hats off to—used to express admiration for someone who has achieved something or done something praiseworthy向…致敬hats off to them for agreeing to work for the day to raise money.向同意在筹款日参加工作的人们。
